Finding the Third Proportional to 18,865.69 and 39,979.69

Step by Step Solution

1. Step 1: Write the proportion equation
   18,865.69 : 39,979.69 = 39,979.69 : x
2. Step 2: Convert to fraction form
   18,865.69/39,979.69 = 39,979.69/x
3. Step 3: Cross multiply
   18,865.69x = 39,979.69 × 39,979.69
4. Step 4: Simplify right side
   18,865.69x = 1,598,375,412.60
5. Step 5: Solve for x
   x = 1,598,375,412.60/18,865.69
6. Step 6: Final answer
   x = 84,723.94